Authentication of printed papers other articles ensures that a document that purports to be an original document is in fact the original document. For years, a handwritten signature has been one method that human use to authenticate a paper document for authentication by other humans and, more recently, by machines. Handwritten signatures, however, can be forged, may be difficult to authenticate even if they are not forged, and require the manual action of a human signatory who may be unable to sign a large number of individual sheets in a document to ensure authenticity.
In the fields of image processing and cryptography, some techniques for authenticating paper documents rely on detailed scans of printed text or graphics that are formed on the paper or on detailed scans of the structure of the paper. Many existing techniques rely on the identification of random properties of printed marks, including authentication marks that are specifically printed for the purpose of authenticating a piece of paper in a document. Still other techniques rely on high-resolution scanning devices to identify unique and non-cloneable properties of each sheet of paper, such as a pattern of wood fibers in the paper, to authenticate the sheet of paper.
As described above, existing authentication systems often require the production of specific authentication marks or the use of high-resolution scanning equipment that is often unavailable to either the party who produces the document or the party who authenticates the document. Consequently, improvements to systems and methods for authentication of documents and other articles that simplify the process of authenticating and verifying the authenticity of the article would be beneficial.